Sheet metal container body and method of making same



Aug. 6, 1968 J. 5. LATAWIEC SHEET METAL CONTAINER BODY AND METHOD OF MAKING SAME Filed Jari. 19, 1966 2 Sheets-Sheet 1 mvElOrovk 50km es-Laif llec; 3 a 04% 9w CATTORNJEJL/ 6, 1968 J. 5. LATAWIEC 3,395,827

SHEET METAL CONTAINER BODY AND METHOD OF MAKING SAME Filed Jan. 19, 1966 2 Sheets-Sheet 2 cjohn 5.11mi awc'ec. B, dd 04m United States Patent 3,395,827 SHEET METAL CONTAINER BODY AND METHOD OF MAKING SAME John S. Latawiec, Lancaster, Pa., assignor to J. L. Clark Manufacturing Co., Rockford, 111., a corporation of Illinois Filed Jan. 19, 1966, Ser. No. 521,563 Claims. (Cl. 220-76) ABSTRACT OF THE DISCLOSURE A tubular sheet metal container body includes a double interlocked seam extending along one side and a peripheral top bead adapted to telescope and interlock with a depending skirt on a plastic cover for the container. Above the interlocked seam and adjacent the ends of the body bead are flattened tabs which are overlapped with one another to form an overlapping joint between the bead ends and thereby insure an effective seal between the cover and the body at the joint.

This invention relates to a tubular container body formed from a rectangular sheet of metal and having a double interlocked longitudinal seam along one side. The invention has more particular reference to a container having a peripheral top bead adapted to telescope and interlock with a depending skirt on a plastic cover for the container.

The primary object is to provide a novel construction of the joint above the interlocked seam and a more effective seal between the cover and the body end across this joint.

A more detailed object is to provide an overlapping joint between the ends of the body bead instead of a butt joint as in prior constructions.

The invention also resides in the novel method of converting a rectangular sheet into a tubular body with an overlapping joint of the above character.

Other objects and advantages of the invention will become apparent from the following detailed description taken in connection with the accompanying drawings, in which:

FIGURE 1 is a fragmentary perspective view of a container having a sheet metal body embodying the novel features of the present invention.

FIGS. 2, 3 and 4 are fragmentary sections taken respectively along the lines 22, 33 and 4-4 of FIG. 1.

FIGS. 5 and 6 are fragmentary plan and perspective views of the container body.

FIGS. 7 to 10 are perspective views illustrating successive steps in forming the container body.

FIG. 11 is an exploded perspective view of the top part of the body.

In the drawings, the invention is shown incorporated in a tubular body 10 of sheet metal and generally rectangular cross-section formed around its upper end with a head 11 adapted to telescope with a skirt 12 depending from a molded plastic cover 13 as shown in FIGS. 2 and 4. In this instance, the bead is a relatively flat hem whose rounded end 14 defines the lip or open end of the body and -becomes wedged and seated tightly in a groove between the outer surface of the skirt 12 and outer skirt 15 depending from the outer peripheral edge of the cover. The free edge 16 of the hem bites into the upper surface of a bead 17 on the inner skirt thus holding the cover securely on the body with the hem sealed tightly against the opposed surfaces of the two skirts.

The body 10 is formed from a thin rectangular sheet 1 8 (FIG. 7) of metal by conventional notching, hemming, body making and seaming operations illustrated in FIGS.

3,395,827 Patented Aug. 6, 1968 8 to 10. Formation of the relatively flat hem 11 may be the initial operation. A so-called St. Louis. seam 20 by which the ends of the sheet are lapped over each other and joined together is formed by first bending end portions of the sheet laterally in opposite directions and then reversely into parallelism with the sheet to form inner and outer flanges or hooks 21 and 22 which are interlocked with each in overlapping relation and flattened into the compact double interlocked seam shown in FIG. 3. In the final assembly, the closed end of the outer hook 22 abuts an offset 23 along one end portion of the sheet while the closed end of the other hook 21 abuts a rib 24 depressed inwardly from the other end portion of the sheet. After the seaming, the extreme upper end of the body is necked down or ofr'set inwardly as indicated at 25 so that the outer periphery of the cover and the skirt 15 Will be substantially fiush with the exposed outer surface of the "body as shown in FIGS. 2 and 4. At its upper end, the seam terminates short of the cover and preferably at the offset 25.

In prior constructions of the above character, the corners of the sheet metal blank have been cut away or notched a distance substantially equal to the overlapping of the sheet ends to form the seam 20 so that, as a result of the body making and seaming operations, the opposed ends of the bead are brought as close as possible into abutment beyond the upper end of the seam. But due to variations inherent in the making of the body by modern automatic machinery, a gap of objectionable width is frequently left between the hem ends thus allowing the container contents, when a fine powder, to sift out during handling of the container after filling.

The present invention avoids such objectionable leakage by employing a lapped joint instead of a butt joint between the ends of the hem. This is accomplished by spacing the ends 26 and 27 of the hem apart a distance approximately equal to the width of the seam 20 and converting the metal of the sheet above the upper ends 28, 29 of the seam hooks into fiat and squared corners or tabs 30 and 31 preferably lying in close face to face contact with their straight upper edges 32 and 33 substantially at the level of the upper closed edge 14 of the hem. In the finished 'body, the outer tab 31 lies in the plane of the outer part 34 of the hem and its outer surface is flush with the outer surfaces of the body and the hem above the offset 25. The inner tab 30 is offset inwardly at 35 (FIGS. 5, 6 and 11) but overlaps the full area of and lies flat against the tab 31. Thus, when the cover is assembled on the body, the upper edge 32 of the fiat outer tab 31 bears and is pressed against the inner surface of the resilient skirt 15 as shown in FIG. 4 all the way across the gap between the hem ends 26, 27. As a result, the tab 31 coacts with the hem to provide an uninterrupted sealing surface around the entire periphery of the body lip. By compressing the tabs into face to face contact above the upper end of the seam, leakage of the container contents around the ends of the corners is prevented effectually.

The foregoing construction is formed without modifying the hemming, body making, and seaming operations and by a simple change in the notching of the corners of sheet metal blank 18. Thus, the upper corners of the blank are formed with two notches 38 and 39 and 38' and 39' instead of one as when a butt joint is to be formed between the hem ends. The combined width of the notches of each pair lengthwise of the sheet is equal substantially to the full peripheral width of the hooks 21 and 22 of the seam 20 while the bottoms of the notches 39 and 39' are spaced from the upper edge of the sheet a distance corresponding to the desired spacing of the upper ends 28 and 29 of the seam from the lip of the body in the final assembly. The depths of these notches 39 and 39' differs somewhat so that in the final assembly, the end 28 of the outer hook 22 will be spaced somewhat below the end 29 of the inner hook 21 as shown in FIGS. 4, 6 and 11. The width of the notches 39 and 39 is approximately equal to the width of the final seam 20. The width of the notches 38 and 38' is equal to the desired final spacing of the hem ends 26 and 27 and their depth is slightly greater than the width of the hem so that the upper edges of the corner tabs 30, 31 will be disposed close to the level of the body lip 11.

With the blank notched as above described and during the conversion into the final body, the inner walls 40 of the notches 38 and 38' become the ends 26 and 27 of the hem, while the bottoms 41 of these notches become the tops 36 and 42 of the tabs 30 and 31. The sides 43 of the notches 39 and 39 become vertical edges 44, 45 of the tabs while the bottoms 46 become the upper edges 28 and 29 of the seam hooks 21 and 22.

I claim as my invention:

1. A container body comprising a tube formed from a rectangular sheet of metal with the ends of the sheet overlapping each other along one side of the tube and each bent reversely to form parallel sided hooks interlocked with each other into the form of a double interlocked seam terminating short of the top of said body, a reversely bent bead of arcuate cross-section formed from said sheet around the top of the body with its free edge facing downwardly and its ends circumferentially spaced apart a distance to leave a gap above the upper end of the seam approximating the width of said seam, and tabs formed out of the corner portions of said sheet above said seam and between said head ends and overlapping one another to close said gap substantially to the top of said body.

2. A container body as defined in claim 1 in which said tabs lie in substantial face to face contact and the outer surface of the outer tab at the top thereof is flush with the outer surface of said bead and body.

3. A container body as defined in claim 1 in which the corners of said tabs adjacent said head ends are substantially square with their upper edges substantially flush with the top of said body.

4. A container bodyas defined in claim 1 in which the upper ends of said seam hooks terminate at different levels below said tabs.

5. The method of forming a tubular container body having a double interlocked seam along one side and a narrow head of arcnate cross-section along the top edge, said method including the steps of, notching two corners of said sheet at opposite ends thereof to form an inner squared notch corresponding in depth to the width of said head and a second deeper squared notch whose bottom eventually defines the upper end of said seam, bending the longitudinal edge of said sheet down to the bottom of said inner notch laterally and reversely to form said head, bending the ends of said sheet outwardly and reversely beyond the inner side of said second notch to form parallel sided hooks, rolling said sheet into a tube with said hooks interlocked with each other and the ends of said head spaced apart circumferentially of the tube end, and compressing the overlapped end portions of the sheet to form said seam with the adjacent portions of the sheet flush with each other and to bring the overlapping corners of the sheet between said bead ends and above the ends of said hooks substantially into face to face contact with the outer one of said corners flush with the outer surface of the tube.

References Cited FOREIGN PATENTS 864,492 4/1961 Great Britain.

JAMES B. MARBERT, Primary Examiner. 

